SCREENING OF SHORT DURATION RICE GENOTYPES FOR ZINC EFFICIENCY
Jegadeeswari D, Chitdeshwari T, Boominathan PRice genotypes, Screening, Zn use efficiency, Bio-fortification25-33February Issue - 2019Zn (Zn) deficiency in tropical soils affects nutritional quality of food grains and to secure nutritional quality, one potential option is the ‘agronomic bio-fortification’ which depends mainly on genotypic efficiency to absorb and accumulate more of Zn into grains. To identify the rice genotypes having better ability to absorb and translocate more Zn into grains, a field experiment was conducted with 15 short duration rice genotypes on a Zn deficient sandy clay loam soil with and without Zn addition. A split plot design was adopted using Zn treatment in main plots, as M1: control (only recommended dose of N,P, and K without Zn) and M2 : recommended dose of N, P, and K with Zn (100 kg ZnSO4 ha-1 as soil application + 0.5% as foliar application thrice at 50% flowering, milk and dough stages) and the selected genotypes as sub plots. Results of present study revealed that, Zn application significantly increased the average grain yield (13.5%) and grain Zn content (37 to 55 %) over control. The rice genotypes, CO 47 performed better with higher grain yield of 5980 and 6750 kg ha-1 respectively under both with and without Zn fertilization. Higher grain yield index was noted with CO 47, and CO 51 (92.7) followed by ADT 45 (88.0) while the highest grain Zn uptake index was noted with CO 47 (40.4). Based on the yield and Zn uptake efficiency, the genotypes CO 47, CO 51, ADT 36, ADT 37, MDU 5, MDU 6, TKM 12, IR 50 were found efficient and responsive to Zn fertilization thus can be utilized for Zn bio-fortification. The rice genotypes TPS 5, Anna 4, CB 14508 are highly inefficient and susceptible to Zn deficiency which needs Zn fertilization without it the yield loss in unavoidable.